A novel antimicrobial composite: ZnAl-hydrotalcite with p-hydroxybenzoic acid intercalation and its possible application as a food packaging material

Microbial contamination poses a great threat to people's life and health. In this paper, p-hydroxybenzoic acid (PHBA) was intercalated into layered double hydroxides (LDHs, with Zn : Al molar ratio = 4 : 1); the former possesses the antifungal effect for Candida albicans, and the latter shows the best antibacterial effect for Staphylococcus aureus. The sample was characterized by XRD, FT-IR spectroscopy and TG-DTA. Its sustained-release property was studied by a release experiment. Finally, ZnAl-PHBA-LDH (Zn : Al = 4 : 1) was dispersed into the solution of gelatin to obtain a food packaging film; antimicrobial experiments showed that the gelatin film of ZnAl-PHBA-LDH (Zn : Al = 4 : 1) (ZPL4) could effectively inhibit the activity of Staphylococcus aureus and Candida albicans. The experimental results confirm the application of ZPL4 in the field of food antimicrobial packaging.